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<br />Coal Creek - 5 - July 13, 1988 <br />'F. A drop structure should be placed at the upstream end of mining. <br />g. A design should be presented for the post-mining channel. A <br />longitudinal profile should be shown relative to present day <br />conditions. The position of the channel nested within the context <br />of the mining pits should be shown. Sufficient cross-sections <br />should be presented based on uniform channel reaches. F{ydraulic <br />design parameters at these cross-sections should be presented. <br />h. A revised discussion, supported by quantitative information where <br />possible, should be provided which describes ground water levels <br />and depletions expected, resulting changes in baseflow, and effects <br />on sediment transport and channel stability within the affected <br />area and in a upstream and downstream direction. <br />6. The lower portion of the tributary which enters Coal Creek from the east <br />'side in Phase D of mining will be mined out. Apost-mining channel <br />should be defined for this section between the edge of the pit and the <br />confluence with the post~nining Coal Creek channel. <br />7. 'fhe designs proposed for headcut control on each of the side tributaries <br />are adequate. <br />Exhibit E - Reclamation Plan <br />8. The seed mixtures include a shrub but do not include a legume. The <br />Division suggests a legume, such as purple prairieclover, be included in <br />:he seed mix. <br />9. [)u ring our inspection, leafy spurge was noted to occur over a large <br />extent of the valley bottom. Also, the extent of weeds on the site was <br />tcpparent and may pose problems during revegetation of the site. Mowing <br />is mentioned as a control for weeds should a signifiicant invasion occur. <br />slave additional measures, particularly for leafy spurge, been considered <br />1'or controlling noxious weeds? <br />10. 1'he perimeter access road in Section 11 is proposed as a permanent <br />_;tructure. As this road is not a pre-existing feature, and no <br />documentation is provided that the landowner desires this road to remain <br />as part of the post-mining land use, the road should be reclaimed as part <br />of the plan. The reclamation plan should be revised, or written <br />documentation provided as appropriate, on the final disposition of roads <br />on the site. <br />Exhibit F - Reclamation Plan Map <br />11. Any changes to the reclamation plan map required due to changes in the <br />mine plan should be shown on a revised Exhibit F. <br />